Nanohybrid shish kebab structure and its effect on mechanical properties in poly(L‐lactide)/carbon nanotube nanocomposite fibers

In our previous work, the formation of a nanohybrid shish kebab (NHSK) structure was successfully achieved in helical polymer systems promoted by using single‐walled carbon nanotube (CNT) bundles with a unique ‘groove structure’, which is of great crystallographic interest. To further investigate the effect of surface groove structure of CNT bundles on the formation of NHSK structure in helical polymer systems, in the work reported here double‐walled carbon nanotube (DWNT) fibers with bundle structure were used as nucleating agents and orientation templates for poly(L ‐lactide) (PLLA) crystallization. A fine NHSK structure with controlled lateral size and period of kebabs was successfully obtained under various experimental conditions by using DWNT bundles. This could be due to the geometric confinement effect of the surface groove structure of the DWNT bundles, which could facilitate the orientation of PLLA chains along the DWNT axis and the lateral formation of a stable nucleus. Our work suggests an efficient method for the functionalization of CNTs with biocompatible PLLA, which may have some potential applications in biomedical areas. In addition, it is demonstrated that the formation of NHSK structure can effectively improve the physical bonding between PLLA and nanotubes, thus significantly improving the mechanical properties of PLLA/CNT nanocomposite fibers. Copyright © 2012 Society of Chemical Industry